Electrical connector



Sept. 2l, 1948. R. J. VIOLETTE ELECTRICAL CONNECTOR Filed Aug. 8, 1945Patented Sept. 21, 1948' UNITED STATES P FFICE (Granted -under the actof amended April 30, 1928: 370 0.,

`This invention relates to electrical coupling devices for use withcoaxial transmission lines and. more particularly, to an improvedconnector device or adaptor designed especially for coupling a soliddielectric coaxial transmission line to the center electrode terminal ofan electron discharge tube-operating at ultra high frequencies.

The invention is particularly applicable to those systems which employedpressurized R.F. lines. -Such systems are well known, and as the presentinvention relates only to the coupling means for connecting a soliddielectric coaxial output cable to the pressurized enclosure or outershield member surrounding an electron discharge tube, it is thought tobe unnecessary tov illustrate and describe the entire system in 'furtherdetail.

Accordingly, one object of the invention is the provision of means forelectrically coupling a coaxial cable to the output terminal of anelec;-

' tron discharge tube anda portion of its shielding container. l

Another object of the invention is'to provide an improved output leadconnector device for coupling an electron discharge tube' to 'a coaxialtransmission line in such a way that the anode cap of the tube will'beconnected to the inner conductor and the tube shielding structure willbe securely connected to the outer conductor.

A further object of the invention is to provide an 'easily assembledoutput lead connector device which will maintain proper electricalconnections between the tube and a coaxial transmission line of the sizeto which the connector is designed to be attached.

Astill further object of the invention is to provide an electricaloutput connector oi' the above character which will improve theimpedance match at the point oi' connection between the coaxialtransmission line and the electron discharge tube. v Still anotherobject of the invention is to provide an electrical coupling connectorwhich will permit small variations in the positioning of the electrodecap terminal 'with respect to the central contact of the tube and yetwill avoid strain of the glass portions oi the tube adjacent to the capterminal. A further object of the invention is to provide a means ofthis character which will aord both a pressure seal and an electricalconnection which will withstand the normal pressurizing of the gas lineotsuch systeirisl without pressure leaks adjacent to the point where theconnector joins the cable as well as aording a breakdown path ot March3, 1883, an

greater dielectric strength at such point of connection.

A better understanding of the objects, features, and advantages of thepresent invention will be obtained from the following detaileddescription ci a practical embodiment thereof when read in conjunctionwith the accompanying drawing whose single ligure shows, insubstantially vertical longitudinal section, the improved output leadconnector device of ythe invention as applied to an electronic tube tocouple the latter to a solid dielectric coaxial cable, therepresentation being partly diagrammatic and partly in detail.

Referring more particularly to the drawing, there is shown a connectordevice which comprises a tubular metallhousing I0 having a reduced neckportion I2 o! considerably smaller diameter connected to an enlargedhollow cylin- The neck I2 includes inner and outer concen- I tricannular' sleevelike portions I6 and Il, the inner sleeve I8 being spacedfrom the outer sleeve I1 by an annular recess I8 which extends axiallyinwardly o! the neck I2 from its outer end. The neck portion I2 of thehousing is externally screw-threaded, as shown at I9, and is providedwith an annular flange or shoulder 2Il which forms the inner end wall ofthe reentrant recess I8. l

The inner sleeve I6 has. a conically tapered outer surface forming oneside wall oi' the recess I8', as shown at 2|, and is provided with acylindrical axial bore 22.

Within the recess I8 of the neck I2 is located a Bland sleeve 24 in theform of a short hollow cylinder of resilient rubber having an outer'annular metal ferrule 25 with its annular base adjacent to the innerend face of the annular flanged gland nut 26, which is screwed onto thethreaded portion I9 o! the neck I2.

In the operation of securing the coaxial cable 21 to the housing. thecable is led successively through the respective coaxial openings in theannular nut 26, the gland sleeve 24, and the inner sleeve I6 of the neckI2, after which the cable-end enters the interior of the housing proper.Before positioning the cable 21 inside the housing I0, a length of theouter braided metallic conductor 28 with its plastic covering 28' of thecable is removed to expose a portion oi the intermediate soliddielectric layer 29 which surrounds the inner central metallic conductor30 of the cable. A short length of the exposed dielectric layer 29adjacent to the cable -end is sulator 33 of also removed to bare theinner central conductor Il th 4rebeneath, which is screw threaded at itsfree e d 3|, all of which is clearly illustrated in the drawing. Thecable is then forced inward of the neck of the housing until thestripped end of 'the outer conductor 2l abuts against the shoulder 2li!!the course the conical surface of the sleeve II is forced under theouter conductor 2l and between it and the adjacent dielectric layer 2lto "produce a wedging action which acts to spread open and flare thisend of the outer conductor while at the same time making good electricaland mechanical contact with the undersurface thereof. The flanged glandnut 20 is now tightened thereby forcing the rubber .glandsleeve 24further into the recess il, thereby compressing the sleeve materialtightly against the outer surface of the now flared end of the outerconductor 2| of the cable.

Within the housing is located a double-cone inpolyethylene having one ofits conical surfaces adjacent to the inner surface of the taperedportion l of the housing i8. The cone 8l has a central opening extendingaxially therethrough, the opening being formed of the conically recessedsection 35 whose inner smaller diameter end communicates with acylindrical recess within which is accommodated the bared end yportionof the dielectric layer 29 which extends through the neck I2 into theinterior of the housing I0.

The inner conductor n of the cable projects completely through andsomewhat beyond the central conical recess l5 and has 'screwed onto itsextended screw-threaded end portion 3i a nut Il which abuts the outerend of the metallic conically tapered plug or wedge 40 which is slidablyfitted upon the inner conductor 30. Tightening of the nut 38 serves toforce the wedge 40 'into firm seating"v engagement with the conicalsides of the recess 35. The wedge 40 and th-at por- I tion of therdielectric layer 29 of the cable which is housed within the recess 3Bserve to retain the cone 3l supported in the desired relationship withrespect to the housing Iii. A dielectric washer 4i of polyisobutyleneabuts the inner end of the cylindrical recess 38 and the opposing end ofthe dielectric layer 29 of the cable to provide a yieldable dielectricmaterial between the polyethylene Ycone insulator 33 and the soliddielectric layer 29 of the cable whereby there will be maintained acontinuity of dielectric protection with no air space at the junctionpoints which might give rise to electrical andpressure breakdowns.

A stepped coupling 42 has an enlarged annular or cup-like base 43 whichis adapted to be screwed onto the reduced screw-threaded portion 44 atthe enlarged end of the conical wedge 40. A split sleeve connector 45,which h-as insertible connection on the terminal contact 46 at theend-of the output lead 41 from a transmitter tube, is slidably mountedupon the small cy-v lindrical step 48 of the coupling 42, the connector45 being secured thereto by means of the flexible metal bellows ySil.Any slight variation in the position of the center contact 46 of thetube output lead 41 is taken care of by the bellows 50 which vpermitsappropriate lateral and longitudinal movement of the contact orconnector 45 about the step 48 of the coupling 42 between the abutment5I thereof and the enlarged head I2 of the screw 53 which is screwedinto the end of the step 4I. 'I'he flexible mounting arrangement of thesleeve connector 45 thus PIQ- of which movement 4 4 vided also allowsfor vibration without imposin! heavy strain on the fragileglass-to-metal seals of the tube (not shown). The housing Il, nut 2i,conical wedge 4l, terminal connector 4l, bellows Il, stepped coupling 42and stop-screw l! are each preferably silver-plated to increase theirsurface conductivity.

The larger end of the housing III is provided with an enlarged annularflange l5 which, in cooperation with the annularly flanged nuttherearound. forms fastening or attaching means distal from the neckportion I2 for securing the housing Il to a suitable screw threadedflange Il of the outer shield member 4Il which surrounds the electrondischarge tube (not shown).

The particular cable constitutes no part of the present invention exceptinsofar as the layer 2l is solid dielectric filling and substantiallycoextensive with the inner and outer conductors of said cable. The layer2l underneath the plastic outeil covering 2l' may comprise copper braid.

It will be clear from the foregoing description that the structuralarrangement of this connector is one which not only offers an impedancematch between the cable and the electronic tube to which it is attached,but also it protects the pressurized gas line from loss of pressurewhenever such a system is employed.

While there has been described a preferred embodiment of the invention,it will be obvious to those skilled 'in the art that various changes andmodifications may be made therein without departing from the spirit ofthe invention, and it is, therefore, to be distinctly understood that nolimitations are intended other than are imposed by the scope of theappended claims and limited by the prior art.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout thepayment of any royalties thereon or therefor.

What is claimed is:

1. A connector for solid dielectric coaxial cables comprising a tubularhousing of electrical conducting material fixedly secured andelectrically connected to the outer conductor of said cable at one endthereof, flexible connector means within said housing to electricallyconnect the inner conductor of said cable to the central output terminalcontact of an electron 4discharge tube, said last named means includinga bellows member operative to absorb the mechanical stresses incident tolateral and longitudinal displacement of said tube contact with respectto the axis of said inner conductor, a tapered dielectric memberconcentrically supporting said connector means within said housing andoperative to provide an impedance match between said cable and saidhousing, and fastening means movably mounted on said housing forsecuring the housing to the shield structure normally enclosing saidelectron discharge device.

2. A connector for solid dielectric coaxial cables comprising a tubularhousing of electrical conducting material having a reduced neck portiondetachably secured and electrically connected to the outer conductor ofsaid cable at one end thereof,` flexible connector means within saidhousing to electrically connect the inner ccnductor of said cable to thecentral output terminal contact of an electron discharge tube, said lastnamed means including a bellows member operative to absorb themechanical stresses incident to lateral and longitudinal displacement ofsaid tube contact with respect to the axis of said inner conductor, atapered dielectric member concentrically supporting said connector meanswithin said housing and operative to provide an impedance match betweensaid cable and said housing, and fastening means rotatably mounted onsaid housing at the end thereof distal from said neck portion forsecuring the housing to the shield structure normally enclosing saidelectron discharge device.

3. An electrical connector comprising a tubular metallic housing havinga neck portion at one end, expander means in said neck to firmly engageand electrically connect the outer conductor of a coaxial transmissionline to said housing, ilexible connector means for electrically couplingthe inner conductor of said line to the output terminalY of an electrondischarge tube, said last named means including a bellows memberoperative to absorb the mechanical stresses incident to lateral andlongitudinal displacement of said tube conf tact with respect to theaxis of said inner conductor, a tapered dielectric member concentricallysupporting said connector means within said housing and operative toprovide an impedance' match between said cable and said housing, andreleasable attaching means for securing said housing and ,electricallyconnecting it to a shield enclosure member normally surrounding saidelec?` tron discharge tube.

4. An electrical connector comprising, a, tubular electricallyconductive housing having a neck portion at one end, a conductive sleevemember within said neck having a tapered expander portion for insertionbeneath and in engagement with the undersurface of the end portion ofthe outer conductor of a coaxial transmission line to thereby enlargeand nare said conductor end, means arranged to firmly engage and gripthe said outer conductor of said coaxial transmission line therebyestablishing an electrical and ,mechanical connection between said outerconductor conductor and maintaining it along the central axis of saidhousing, coupling means including lar conductive housing having atubular neckV portion, means within said neck having a conically taperedVexpander portion adapted to be inserted beneath and along the outerconductor end oi said cable to enlarge and flare said conductor end whenthe cable end is forced thereon, compressible sealing means slidablewithin said neck toward said cable end into tight sealing relation withthe outer surface of said outer conductor, means on said neck for movingsaid sealing means into sealing engagement with said outer conductorwhen said cable-end is inserted through said neck to project into theinterior of said housing. a dielectric member within said housing aroundsaid cable-end, said dielectric member having inwardly directed from oneside a conically-tapered central opening the smaller end of whichcommunicates with and is coaxial with respect to a central cylindricalrecess for accommodating the dielectric end portion of said cable-endextending inwardly from the opposite side ot said dielectric member. aconductive coniand said housing, a conductive iiexible connector lelement within the interior of said housing electrically connecting saidinner conductor therein to the output terminal contact of an electrondischarge tube, said connector element including a bellows memberoperative to absorb the mechanical stresses incident to lateral andlongitudinal displacement of said tube contact with respect to the axisof said inner conductor. a tapered dielectric member concentricallysupporting said connector element within said housing and operative toprovide an impedance match between said cable and said housing, andfastening means establishing electrical connection therebetweentodetachably secure said housing to a shield member normally enclosingsaid electron discharge tube.

5. In a device for connecting a coaxial cable having an inner and anouter conductor to a terminalof an electron discharge tube and itsshield respectively. impedance matching means including said cable-end.a tubular metallic housing, connector means on said housing disposedexteriorly of the outer conductor of the coaxial cable to connect itelectrically to said housing. an insulator around and supported by saidinner cal wedge within said conically tapered recess and ofcorresponding taper, said wedge being slidable along the bared end ofsaid inner conducwrof the cable, means for moving said wedge into tightengagement with said dielectric member, coupling means carried by theinner conductor ofsaid cable ,to electrically connect the latter to theoutput terminal of the electron discharge tube, said coupling meansincluding a bellows member operative to absorb the mechanical stressesincident to lateral and longitudinal displacement of said tube' contactwith respect to the axis of said inner conductor, and fastening meansfor securing the housing to the shield structure normally surroundingand enclosing said electron discharge device.

RICHARD J. VIOLETTE.

REFERENCES crrm) The .following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Dato 1,718,817 Greene June 25, 1925y1,841,473 Green Jan. 19, 1932 2,167,201 Dailanbach July 25, 19392,173,643 Moser Sept. 19, 1939 2,177,268 Stone et al Oct. 24, 1939

